The arrangement of an electronic semiconductor component with the active side downward (face down) on a carrier system, so that there is at least in certain portions an edge between the semiconductor component and the carrier system in a way corresponding to the topography of the semiconductor component, is very frequently encountered in semiconductor technology. A gap may be required for technical process-related reasons and the medium flowing around the gap is chosen such that the gap is optimally filled under the influence of its capillary action, such as, for example, for the underfilling of the electronic semiconductor component in flip-chip technology.
Alternatively, the capillary action of the gap may lead to undesired flowing of the liquid medium under the semiconductor component. In any event, it is known that the capillary action depends on the width of the gap and the surface tension of the liquid medium as its material-typical property.
The flowing of a medium, in particular an etching medium, under the semiconductor component is to be prevented, since in the case of face-down mounting of the semiconductor component it can lead to undefined etching of its active side and, as a result, damage or even destruction of the electronic component.
This aspect is becoming increasingly significant in thin-wafer technology, since ever larger wafers are being produced at ever lower cost and in an ever thinner form, and ever greater requirements have to be met with respect to safe handling of the thin wafers as products. This requires the development of carrier technologies that allow safe handling of the thin wafers during production.
The handling of the electronic semiconductor components, in this case in the wafer array, on a carrier system leads to the active side of the electronic semiconductor components being influenced in the way described, in particular during wafer thinning by grinding in the presence of an abrasive liquid medium and by wet-chemical back etching of the wafer, the components being located within the gap in the face-down arrangement of the wafers on the carrier system and likewise exposed to the aggressive media as a result of the capillary action of the gap.
In the past, the damage to the semiconductor components has been minimized by frequent changing of the carrier system or by the thin wafers being handled for a short time, which however leads to a special effort being required and to increased costs, also on account of the susceptibility of the thin wafers to fracture.
A further possibility for protecting the active side of wafers from the aggressive media is at present to attach an adhesive film to this side. However, the film material drastically limits the temperature range that is available for the further process, generally to below 100° C. A further major disadvantage of this method is that the requirement to remove the film again requires the thin wafer to be of a certain thickness, which must be great enough to withstand the mechanical forces during the detachment of the film. This condition currently restricts the thickness of the thin wafers to about 100 μm. However, future technologies require far smaller wafer and component thicknesses.